Cisco 640-802 Online Practice Questions and Exam Preparation

Cisco 640-802 Online Questions & Answers

• Question 81:

  For what two purposes does the Ethernet protocol use physical addresses? (Choose two.)

  A. to uniquely identify devices at Layer 2
  B. to allow communication with devices on a different network
  C. to differentiate a Layer 2 frame from a Layer 3 packet
  D. to establish a priority system to determine which device gets to transmit first
  E. to allow communication between different devices on the same network
  F. to allow detection of a remote device when its physical address is unknown
  A. to uniquely identify devices at Layer 2
  E. to allow communication between different devices on the same network

  ---

  Physical addresses or MAC addresses are used to identify devices at layer 2.

  MAC addresses are only used to communicate on the same network. To communicate on different network we have to use Layer 3 addresses (IP addresses) -> B is not correct.

  Layer 2 frame and Layer 3 packet can be recognized via headers. Layer 3 packet also contains physical address ->.

  On Ethernet, each frame has the same priority to transmit by default ->.

  All devices need a physical address to identify itself. If not, they cannot communicate ->.

• Question 82:

  What will be the result if the following configuration commands are implemented on a Cisco switch?

  Switch(config-if)# switchport port-security Switch(config-if)# switchport port-security mac-address sticky

  A. A dynamically learned MAC address is saved in the startup-configuration file.
  B. A dynamically learned MAC address is saved in the running-configuration file.
  C. A dynamically learned MAC address is saved in the VLAN database.
  D. Statically configured MAC addresses are saved in the startup-configuration file if frames from that address are received.
  E. Statically configured MAC addresses are saved in the running-configuration file if frames from that address are received.
  B. A dynamically learned MAC address is saved in the running-configuration file.

  ---

  In the interface configuration mode, the command switchport port-security mac-address sticky enables sticky learning. When entering this command, the interface converts all the dynamic secure MAC addresses to sticky secure MAC addresses.

• Question 83:

  Before installing a new, upgraded version of the IOS, what should be checked on the router, and which command should be used to gather this information? (Choose two.)

  A. the amount of available ROM
  B. the amount of available flash and RAM memory
  C. the version of the bootstrap software present on the router
  D. show version
  E. show processes
  F. show running-config
  B. the amount of available flash and RAM memory
  D. show version

  ---

  When upgrading a new version of the IOS we need to copy the IOS to the Flash so first we have to check if the Flash has enough memory or not. Also running the new IOS may require more RAM than the older one so we should check the available RAM too. We can check both with the "show version" command.

• Question 84:

  Which two types of NAT addresses are used in a Cisco NAT device? (Choose two.)

  A. inside local
  B. inside global
  C. inside private
  D. outside private
  E. external global
  F. external local
  A. inside local
  B. inside global

• Question 85:

  Refer to the exhibit.

  

  A network administrator attempts to ping Host2 from Host1 and receives the results that are shown. What is the problem?

  A. The link between Host1 and Switch1 is down.
  B. TCP/IP is not functioning on Host1
  C. The link between Router1 and Router2 is down.
  D. The default gateway on Host1 is incorrect.
  E. Interface Fa0/0 on Router1 is shutdown.
  F. The link between Switch1 and Router1 is down.
  C. The link between Router1 and Router2 is down.

  ---

  Host1 tries to communicate with Host2. The message destination host unreachable from Router1 indicates that the problem occurs when the data is forwarded from Host1 to Host2. According to the topology, we can infer that the link between Router1 and Router2 is down.

• Question 86:

  Refer to the graphic.

  

  Host A is communicating with the server. What will be the source MAC address of the frames received by Host A from the server?

  A. the MAC address of router interface e0
  B. the MAC address of router interface e1
  C. the MAC address of the server network interface
  D. the MAC address of host A
  A. the MAC address of router interface e0

  ---

  Whereas switches can only examine and forward packets based on the contents of the MAC header, routers can look further into the packet to discover the network for which a packet is destined. Routers make forwarding decisions based on the packet's network-layer header (such as an IPX header or IP header). These network-layer headers contain source and destination network addresses. Local devices address packets to the router's MAC address in the MAC header. After receiving the packets, the router must perform the following steps:

  1.

  Check the incoming packet for corruption, and remove the MAC header. The router checks the packet for MAC-layer errors. The router then strips off the MAC header and examines the network-layer header to determine what to do with the packet.

  2.

  Examine the age of the packet. The router must ensure that the packet has not come too far to be forwarded. For example, IPX headers contain a hop count. By default, 15 hops is the maximum number of hops (or routers) that a packet can cross. If a packet has a hop count of 15, the router discards the packet. IP headers contain a Time to Live (TTL) value. Unlike the IPX hop count, which increments as the packet is forwarded through each router, the IP TTL value decrements as the IP packet is forwarded through each router. If an IP packet has a TTL value of 1, the router discards the packet. A router cannot decrement the TTL value to 1 and then forward the packet.

  3.

  Determine the route to the destination. Routers maintain a routing table that lists available networks, the direction to the desired network (the outgoing interface number), and the distance to those networks. After determining which direction to forward the packet, the router must build a new header. (If you want to read the IP routing tables on a Windows 95/98 workstation, type ROUTE PRINT in the DOS box.)

  4.

  Build the new MAC header and forward the packet. Finally, the router builds a new MAC header for the packet. The MAC header includes the router's MAC address and the final destination's MAC address or the MAC address of the next router in the path.

• Question 87:

  Refer to the exhibit.

  

  Which rule does the DHCP server use when there is an IP address conflict?

  A. The address is removed from the pool until the conflict is resolved.
  B. The address remains in the pool until the conflict is resolved.
  C. Only the IP detected by Gratuitous ARP is removed from the pool.
  D. Only the IP detected by Ping is removed from the pool.
  E. The IP will be shown, even after the conflict is resolved.
  A. The address is removed from the pool until the conflict is resolved.

  ---

  An address conflict occurs when two hosts use the same IP address. During address assignment, DHCP checks for conflicts using ping and gratuitous ARP. If a conflict is detected, the address is removed from the pool. The address will not

  be assigned until the administrator resolves the conflict.

  (Reference: http://www.cisco.com/en/US/docs/ios/12_1/iproute/configuration/guide/1cddhcp.html)

• Question 88:

  Refer to the exhibit.

  

  A problem with network connectivity has been observed. It is suspected that the cable connected to switch port Fa0/9 on Switch1 is disconnected. What would be an effect of this cable being disconnected?

  A. Host B would not be able to access the server in VLAN9 until the cable is reconnected.
  B. Communication between VLAN3 and the other VLANs would be disabled.
  C. The transfer of files from Host B to the server in VLAN9 would be significantly slower.
  D. For less than a minute, Host B would not be able to access the server in VLAN9. Then normal network function would resume.
  D. For less than a minute, Host B would not be able to access the server in VLAN9. Then normal network function would resume.

  ---

  Spanning-Tree Protocol (STP) is a Layer 2 protocol that utilizes a special-purpose algorithm to discover physical loops in a network and effect a logical loop-free topology. STP creates a loop-free tree structure consisting of leaves and branches that span the entire Layer 2 network. The actual mechanics of how bridges communicate and how the STP algorithm works will be discussed at length in the following topics. Note that the terms bridge and switch are used interchangeably when discussing STP. In addition, unless otherwise indicated, connections between switches are assumed to be trunks.

• Question 89:

  Which spanning-tree protocol rides on top of another spanning-tree protocol?

  A. MSTP
  B. RSTP
  C. PVST+
  D. Mono Spanning Tree
  A. MSTP

• Question 90:

  Which of these represents an IPv6 link-local address?

  A. FE80::380e:611a:e14f:3d69
  B. FE81::280f:512b:e14f:3d69
  C. FEFE:0345:5f1b::e14d:3d69
  D. FE08::280e:611:a:f14f:3d69
  A. FE80::380e:611a:e14f:3d69

  ---

  In the Internet Protocol Version 6 (IPv6), the address block fe80::/10 has been reserved for link-local unicast addressing. The actual link local addresses are assigned with the prefix fe80::/64. They may be assigned by automatic (stateless) or stateful (e.g. manual) mechanisms.